A) Field of the Invention
The present invention relates to a manufacture method for a resin mold assembly.
B) Description of the Related Art
A vehicle lightning instrument, for example, has often a resin mold product constituted of a housing and a lens welded together, the housing being made of light absorbing resin such as acrylonitrile styrene acrylate (ASA), and the lens being made of light transmitting resin such as poly methyl methacrylate (PMMA) and polycarbonate.
JP-A-10-310676 proposes housing composition capable of suppressing cobwebbing phenomenon during hot plate welding in which a hot plate is sandwiched between a lens and a housing to heat and melt the lens and housing and thereafter the hot plate is removed to weld the lens and housing.
JP-A-2000-294013 proposes laser welding in which a lens and a lamp body (housing) are brought into pressed state, a robot radiates a laser beam from the lens side toward the surface of the lamp body to heat and melt the lamp body, melting heat of the lamp body melts also the front portion of a seal leg on the lens side, and the laser beam is scanned along the whole circumference of the lens.
This Publication describes that a positioning groove may be formed on a receiving surface of the lamp body to prevent a positional shift of the seal leg so that laser welding is able to be performed in a state that a predetermined positional relation is held, and even if some burring occurs, the burring is able to be confined in the positioning groove.
JP-A-2001-243812 proposes to incline a bonding plane between a seal leg of a lens and a receiving surface of a lamp body to generate a slip and widen a beam spot diameter.
JP-A-2004-349123 proposes a method of welding a housing and a lens with a laser beam, including a case wherein the lens has a curved surface, in which method on the surface of the lens to be combined with the housing, are disposed an elastic light guiding member compatible with the lens shape and a flat transparent plate, a compressive load is applied through the flat transparent plate to the elastic light guiding member and the lens to make the elastic light guiding member contact the lens closely, and a laser beam is radiated from the flat transparent plate side to heat and melt the contact region of the lens and housing, via the elastic light guiding member and lens.
It cannot be said that a method of welding a resin mold assembly with a laser beam has been developed sufficiently.
It is desired to provide a method of manufacturing a resin mold assembly including a light transmitting resin member and a light absorbing resin member by using a laser beam, wherein the resin mold assembly has tight adhesion, excellent outer appearance, and high bonding strength.